US3045027A

US3045027A - Preparation of ethylene sulfate

Info

Publication number: US3045027A
Application number: US830990A
Authority: US
Inventors: George E Ham
Original assignee: Dow Chemical Co
Current assignee: Dow Chemical Co
Priority date: 1959-08-03
Filing date: 1959-08-03
Publication date: 1962-07-17
Anticipated expiration: 1979-07-17

Description

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United States Patent 3,045,027 PREPARATION OF ETHYLENE SULFATE George E. Ham, Lake Jackson, Tex., assignor to The Dow Chemical Company, Midland, Mich., a corporation of Delaware N0 Drawing. Filed Aug. 3, 1959, Ser. No. 830,990

13 Claims. (Cl. 260327) The present invention relates to a new and useful method for preparing alkylene sulfates and is more particularly concerned with a novel process which employs readily available starting materials for preparing alkylene sulfates, particularly ethylene sulfate and polymers thereof.

One prior known method for the preparation of ethylene sulfate is the reaction of ethylene dibromide and silver sulfate. One of the major drawbacks to this process is the employment of expensive reactants. Therefore, it would be advantageous to provide a process which employs less expensive reactants.

It is an object of the present invention to provide a process for making alkylene sulfates which employs readily available starting materials. A further object of the present invention is to provide a process which employs inexpensive reactants. These and other objects will become apparent to those skilled in the art from the following specification and claims.

It has now been found that alkylene sulfates can be prepared by reacting an alkylene oxide having from 2 to carbon atoms, inclusive, with sulfur trioxide in 1,4- dioxane or p-oxathiane (solvents which form a complex with the S0 Conveniently, the sulfur trioxide is slowly mixed with the 1,4-dioxane or p-oxathiane at a temperature of from C. to 25 C., and then alkylene oxide slowly passed into the mixture. Good results are obtained when the reactants are employed in substantially equimolecular proportions. The desired product is obtained from the reaction mixture by fractional distillation, sublimation or the like.

In accordance with the present invention, one manner of carrying out the process comprises adding slowly in a dropwise manner sulfur trioxide to 1,4-dioxane or oxathiane with stirring and cooling. The addition results in an exothermic rise in temperature necessitating the employment of external cooling to maintain the temperature of the reaction mixture from about 10 to about 25 C. During the addition a precipitate forms which is believed to be an addition product of the sulfur trioxide and the 1,4-dioxane or oxathiane. Upon completion of the addition of sulfur trioxide an alkylene oxide, such as ethylene oxide, is slowly passed into the solvent SO reaction mixture. When approximately an equimolecular quantity of'the alkylene oxide, based on sulfur trioxide, has been added, the solvent SG precipitate which had formed substantially completely dissolves. The addition of the alkylene oxide can be continued until a 5 to 10 or more percent excess of oxide has been added. Upon completion of the addition of the alkylene oxide, the reaction mixture is distilled under vacuum to remove the solvent and recover a viscous liquid which on sublimation under vacuum yields the appropriate alkylene sulfate.

The alkylene oxides which can be employed in accordance with the present invention are the lower vicinal alkylene oxides from 2 to 5 carbon atoms, inclusive. Some of such compounds are, for example, ethylene oxide, 1,2-propylene oxide, 1,2-butylene oxide, 1,2-isobutylene oxide, 2,3-butylene oxide, 1,2-pentylene oxide, and the The solvents which can be employed in accordance with the present invention are those organic solvents, which form with sulfur trioxide a complex or addition product, and which complex or addition product will dissociate under the conditions hereinbefore set forth to free the S0 for reaction with the alkylene oxide. Two known compounds which are operative in the method of the present invention and which form the aforesaid complex or addition product are 1,4-dioxane and para-oxathiane.

The following examples illustrate the present invention but are not to be construed as limiting:

Example 1 Dry, redistilled 1,4-dioxane (200 ml.) was cooled and 19.3 g. (0.25 mole) of sulfur trioxide was added dropwise with stirring. By controlling the rate of addition and keeping the mixture cool (ca. 10 C.) the sulfur trioxide could be added in this manner with no charring. During the addition the sulfur trioxide-dioxane addition compound precipitated. After addition was complete, ethylene oxide was passed into the mixture slowly with cooling and stirring. When approximately 0.25 mole of ethylene oxide had been added, the precipitated addition compound product, identified as ethylene sulfate, had the following properties: M.P. 96-97 C. Analysis: Found, C, 19.86;

H, 3.36. Calculated for C H O S, C, 19.35; H, 325.

Example 2 ;comprises the steps of reacting sulfur trioxide with 1,4-

dioxane at a temperature from about 10 to about 25 C. to produce a dioxane-sulfur trioxide addition complex; subsequently reacting the so formed complex with a lower vicinal alkylene oxide having from 2 to 5 carbon atoms, inclusive at a temperature between about 10 C. and about 25 C.

3. A method for preparing alkylene sulfates which comprises the steps of reacting sulfur trioxide with paraoxathiane at a temperature of from about 10 to about 25 C. to produce a para-oxathiane-sulfur trioxide addition complex; subsequently reacting the so formed complex with a lower vicinal alkylene oxide having from 2 to 5 carbon atoms, inclusive at a temperature between about 10 C. and about 25 C.

4. The method of claim 2 wherein said alkylene oxide is ethylene oxide. 7

5. The method of claim 2 wherein said alkylene oxide is propylene oxide.

6. The method of claim 2 wherein said alkylene oxide is butylene oxide.

7. The method of claim 2 wherein said alkylene oxide is 1,2-pentylene oxide.

8. The method of claim 2 wherein said alkylene oxide is isobutylene oxide.

9. The method of claim 3 wherein said alkylene oxide is ethylene oxide.

Patented July 17, 1962.

3" a a h- 10. The method of claim 3 wherein said alkylene oxide References Cited in 1116 file of this P 1s propylene oxide. UNITED STATES PATENTS 11. The method of claim 3 wherein said alkylene oxide i butylene Oxide 2,684,977 Viafd "T July 27, 1954 12- The method Of claim 3 wherein said alkyleng oxide 5 2805228 Smith Sept 1957 is 1,2-penty1ene oxide. FOREIGN PATENTS 13. The method of claim 3 wherein said alkylene oxide 1,029,382 Germany May 8, 1958 is isobutylene oxide. 1,049,870 Germany Feb. 5, 1959

Claims

1. A METHOD FOR PREPARING ALKYLENE SULFATES WHICH COMPRISES REACTING SULFUR TRIOXIDE WITH A LOWER VICINAL ALKYLENE OXIDE HAVING FROM 2 TO 5 CARBON ATOMS, INCLUSIVE, AT A TEMPERATURE BETWEEN 10* AND ABOUT 25*C. SAID REACTION BEING CARRIED OUT IN THE PRESENCE OF A SOLVENT SELECTED FROM THE GROUP CONSISTING OF 1,4-DIOXANE AND PARA-OXATHIANE.

2. A METHOD FOR PREPARING ALKYLENE SULFATES WHICH COMPRISES THE STEPS OF REACTING SULFUR TRIOXIDE WITH 1,4DIOXANE AT A TEMPERATURE FROM ABOUT 10* TO ABOUT 25*C. TO PRODUCE A DIOXANE-SULFUR TRIOXIDE ADDITION COMPLEX; SUBSEQUENTLY REACTING THE SO FORMED COMPLEX WITH A LOWER VICINAL ALKYLENE OXIDE HAVING FROM 2 TO 5 CARBON ATOMS, INCLUSIVE AT A TEMPERATURE BETWEEN ABOUT 10*C. AND ABOUT 25*C.